US4559238A - Method of making a field effect transistor with modified Schottky barrier depletion region - Google Patents
Method of making a field effect transistor with modified Schottky barrier depletion region Download PDFInfo
- Publication number
- US4559238A US4559238A US06/399,739 US39973982A US4559238A US 4559238 A US4559238 A US 4559238A US 39973982 A US39973982 A US 39973982A US 4559238 A US4559238 A US 4559238A
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- United States
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- ohmic contacts
- electrode
- gate
- region
- layer
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- Expired - Fee Related
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- 230000004888 barrier function Effects 0.000 title claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 title claims abstract 3
- 230000005669 field effect Effects 0.000 title abstract description 4
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims abstract description 8
- 239000000758 substrate Substances 0.000 claims abstract description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910052751 metal Inorganic materials 0.000 claims abstract description 5
- 239000002184 metal Substances 0.000 claims abstract description 5
- 239000004065 semiconductor Substances 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 19
- 229920002120 photoresistant polymer Polymers 0.000 claims description 6
- 229910005230 Ga2 O3 Inorganic materials 0.000 claims description 5
- AJNVQOSZGJRYEI-UHFFFAOYSA-N digallium;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Ga+3].[Ga+3] AJNVQOSZGJRYEI-UHFFFAOYSA-N 0.000 claims description 5
- 229910001195 gallium oxide Inorganic materials 0.000 claims description 5
- 229910052733 gallium Inorganic materials 0.000 claims description 4
- 230000001590 oxidative effect Effects 0.000 claims description 2
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 claims 3
- 238000000151 deposition Methods 0.000 claims 3
- 238000010849 ion bombardment Methods 0.000 claims 2
- 230000000873 masking effect Effects 0.000 claims 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims 1
- 229910001873 dinitrogen Inorganic materials 0.000 claims 1
- 239000001301 oxygen Substances 0.000 claims 1
- 229910052760 oxygen Inorganic materials 0.000 claims 1
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 2
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 238000004544 sputter deposition Methods 0.000 description 4
- 238000001465 metallisation Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000004381 surface treatment Methods 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005352 clarification Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 238000004347 surface barrier Methods 0.000 description 2
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000003574 free electron Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66848—Unipolar field-effect transistors with a Schottky gate, i.e. MESFET
- H01L29/66856—Unipolar field-effect transistors with a Schottky gate, i.e. MESFET with an active layer made of a group 13/15 material
- H01L29/66863—Lateral single gate transistors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/10—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions with semiconductor regions connected to an electrode not carrying current to be rectified, amplified or switched and such electrode being part of a semiconductor device which comprises three or more electrodes
- H01L29/1025—Channel region of field-effect devices
- H01L29/1029—Channel region of field-effect devices of field-effect transistors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/80—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier
- H01L29/812—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier with a Schottky gate
Definitions
- the present invention regards a MESFET (Metal Semiconductor Field Effect Transistor) type transistor and more precisely a gallium arsenide (GaAs) FET for microwave applications.
- MESFET Metal Semiconductor Field Effect Transistor
- GaAs gallium arsenide
- GaAs MESFET constitutes two parallel ohmic contacts and a gate (electrode or barrier contact) centered between these ohmic contacts positioned on a GaAs substrate which is highly doped and which itself is positioned on a semi-insulating base or substrate.
- a process for realising a recessed barrier electrode presents numerous difficulties.
- the structure cannot be obtained when the barrier electrode is defined, that is deliniated, simultaneously with the two ohmic contacts which are parallel to it by means of a self-aligning process in which, as is well known, the barrier electrode metallization is uniformly deposited on the active layer surface and then deliniated by chemical etch.
- the object of this invention is to modify the depth of the electron-depletion region in the transistor channel, that is the section under the gate and in the gaps between the gate and the ohmic contacts by physical-chemical means without having to modify the structural configuration of the transistor.
- the above effect can be obtained either by reducing the depth of the depleted region under the two sections between the gate and the ohmic contacts, or by increasing the depth of the depleted region under the gate.
- the inventors have searched for a material which when applied to the GaAs surface, produces a reduction in the depth of the depleted region.
- the surface barrier and thus the depletion is determined by the nature of the semiconductor surface active layer and is substantially independent of the type of gate metallization (see for example, "Reactivity and interface chemistry during Schottly-barrier formation of metals on the native oxide of GaAs investigated by X-ray photoelectron spectroscopy" by S. P. Kowalczyk; J. K. Waldrop, R. W. Grant in Applied Phys. Lett., 38 (3) 2 Feb. 1981).
- the inventors have perfected a second procedure for modulating the depleted region of the active layer which avoids the solution of having to recess the gate.
- This procedure consists in treating the section of the active layer surface which is destined to be covered by the gate in such a way as to increase the surface barrier, that is the potential difference between the surface and the bulk of the active layer, which corresponds to a deepening under that section of the region of the active layer depleted of electrons.
- the surface treatment which constitutes an important aspect of the invention consists in subjecting to sputtering (ionic bombardment, with nitrogen) the section of surface in question.
- the sputtering must be light, that is at low power (circa 100 W) and of relatively short duration (circa 2 minutes) in order not to erode away the active layer.
- the intermediate sections between the gate and the ohmic contacts are not treated and as such the depleted region under these sections corresponds to the usual 0.70 V barrier which is typically created by the native oxides.
- FIGS. 1 and 2 are cross sectional views showing prior art versions of the depletion region without modification and with modification by recessing the gate, respectively;
- FIGS. 3-5 are similar views showing modification of the depletion region in accordance with the principles of this invention.
- FIG. 1 is a schematic representation of a GaAs field effect transistor produced by a current technique.
- G indicates the "gate” (i.e. barrier electrode) and OC indicates the ohmic contacts;
- the active layer SA is applied to a semi-insulating substrate SI; the region ZS depleted of electrons in the active layer is deliniated by the dashed line while J represents the electron flux.
- the active layer SA is highly doped (n ⁇ 10 17 cm -3 ) and thin (0.3 ⁇ m). From FIG. 1 the depth W of the depleted region under the gate G and the intervals between each of the ohmic contacts and the gate in absence of the applied voltage is clearly evident. The depth W corresponds to the normal barrier of 0.7 eV typically created by the native oxides.
- FIG. 2 where the symbols are analogous to those in FIG. 1, an analogous transistor illustrating the system proposed in the IEEE publication cited above has been shown.
- the gate G is recessed into a trough parallel to the ohmic contacts OC. From this diagram the particular behavior of the depleted region under the gate and under the gaps between the gate and the ohmic contacts is shown. That is FIG. 2 reveals that the depleted region penetrates into the active layer under the gate more than in the sections under the said gaps. In practice the boundary of the depleted region follows the profile of the active layer surface.
- FIG. 3 for clarification, the effect of a layer a' of silicon nitride deposited between the gaps between the gate G and the ohmic contacts OC is illustrated. This confirming the possibility of varying the depth (W'>W) of the depleted region by covering the active layer in the section between the gate and the ohmic contacts with a suitable material.
- the transistor is subjected to a bombardment (sputtering) with ions of N 2 at a low power (circa 100 W) for approximately 2 minutes.
Abstract
Description
Claims (4)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT48933A/81 | 1981-07-20 | ||
IT48933/81A IT1171402B (en) | 1981-07-20 | 1981-07-20 | FIELD-EFFECT TRANSISTOR WITH METAL-SEMICONDUCTIVE BARRIER EMPTY MODIFIED ZONE |
Publications (1)
Publication Number | Publication Date |
---|---|
US4559238A true US4559238A (en) | 1985-12-17 |
Family
ID=11269077
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/399,739 Expired - Fee Related US4559238A (en) | 1981-07-20 | 1982-07-19 | Method of making a field effect transistor with modified Schottky barrier depletion region |
Country Status (4)
Country | Link |
---|---|
US (1) | US4559238A (en) |
EP (1) | EP0070810B1 (en) |
DE (1) | DE3280244D1 (en) |
IT (1) | IT1171402B (en) |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4640003A (en) * | 1985-09-30 | 1987-02-03 | The United States Of America As Represented By The Secretary Of The Navy | Method of making planar geometry Schottky diode using oblique evaporation and normal incidence proton bombardment |
US4694563A (en) * | 1981-01-29 | 1987-09-22 | Sumitomo Electric Industries, Ltd. | Process for making Schottky-barrier gate FET |
US4706377A (en) * | 1986-01-30 | 1987-11-17 | United Technologies Corporation | Passivation of gallium arsenide by nitrogen implantation |
US4774200A (en) * | 1985-03-26 | 1988-09-27 | Sumitomo Electric Industries, Ltd. | Schottky-gate field effect transistor and method for producing the same |
US4782031A (en) * | 1983-10-19 | 1988-11-01 | Matsushita Electronics Corporation | Method of making GaAs MOSFET with low source resistance yet having satisfactory leakage current by ion-implantation |
US4833042A (en) * | 1988-01-27 | 1989-05-23 | Rockwell International Corporation | Nonalloyed ohmic contacts for n type gallium arsenide |
US4889817A (en) * | 1985-08-08 | 1989-12-26 | Oki Electric Industry Co., Ltd. | Method of manufacturing schottky gate field transistor by ion implantation method |
US5011785A (en) * | 1990-10-30 | 1991-04-30 | The United States Of America As Represented By The Secretary Of The Navy | Insulator assisted self-aligned gate junction |
US5030579A (en) * | 1989-04-04 | 1991-07-09 | Eaton Corporation | Method of making an FET by ion implantation through a partially opaque implant mask |
US5138406A (en) * | 1989-04-04 | 1992-08-11 | Eaton Corporation | Ion implantation masking method and devices |
US5914500A (en) * | 1997-01-21 | 1999-06-22 | Abb Research Ltd. | Junction termination for SiC Schottky diode |
US20050017244A1 (en) * | 2003-07-25 | 2005-01-27 | Randy Hoffman | Semiconductor device |
US20050017302A1 (en) * | 2003-07-25 | 2005-01-27 | Randy Hoffman | Transistor including a deposited channel region having a doped portion |
US20050199967A1 (en) * | 2004-03-12 | 2005-09-15 | Hoffman Randy L. | Semiconductor device |
US20110068348A1 (en) * | 2009-09-18 | 2011-03-24 | Taiwan Semiconductor Manufacturing Company, Ltd. | Thin body mosfet with conducting surface channel extensions and gate-controlled channel sidewalls |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2592225B1 (en) * | 1985-12-20 | 1988-02-05 | Thomson Csf | POWER HYPERFREQUENCY TRANSISTOR |
DE69433738T2 (en) * | 1993-09-07 | 2005-03-17 | Murata Mfg. Co., Ltd., Nagaokakyo | Semiconductor element and method of making the same |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4056642A (en) * | 1976-05-14 | 1977-11-01 | Data General Corporation | Method of fabricating metal-semiconductor interfaces |
US4098921A (en) * | 1976-04-28 | 1978-07-04 | Cutler-Hammer | Tantalum-gallium arsenide schottky barrier semiconductor device |
US4170666A (en) * | 1977-05-11 | 1979-10-09 | Rockwell International Corporation | Method for reducing surface recombination velocities in III-V compound semiconductors |
US4172906A (en) * | 1977-05-11 | 1979-10-30 | Rockwell International Corporation | Method for passivating III-V compound semiconductors |
US4244097A (en) * | 1979-03-15 | 1981-01-13 | Hughes Aircraft Company | Schottky-gate field-effect transistor and fabrication process therefor |
US4310362A (en) * | 1979-06-22 | 1982-01-12 | Thomson-Csf | Method of making Schottky diode with an improved voltage behavior |
US4426765A (en) * | 1981-08-24 | 1984-01-24 | Trw Inc. | Process for fabrication of ohmic contacts in compound semiconductor devices |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2461358A1 (en) * | 1979-07-06 | 1981-01-30 | Thomson Csf | METHOD FOR PRODUCING A SELF-ALIGNED GRID FIELD EFFECT TRANSISTOR AND TRANSISTOR OBTAINED THEREBY |
-
1981
- 1981-07-20 IT IT48933/81A patent/IT1171402B/en active
-
1982
- 1982-06-15 DE DE8282830172T patent/DE3280244D1/en not_active Expired - Fee Related
- 1982-06-15 EP EP82830172A patent/EP0070810B1/en not_active Expired
- 1982-07-19 US US06/399,739 patent/US4559238A/en not_active Expired - Fee Related
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4098921A (en) * | 1976-04-28 | 1978-07-04 | Cutler-Hammer | Tantalum-gallium arsenide schottky barrier semiconductor device |
US4056642A (en) * | 1976-05-14 | 1977-11-01 | Data General Corporation | Method of fabricating metal-semiconductor interfaces |
US4170666A (en) * | 1977-05-11 | 1979-10-09 | Rockwell International Corporation | Method for reducing surface recombination velocities in III-V compound semiconductors |
US4172906A (en) * | 1977-05-11 | 1979-10-30 | Rockwell International Corporation | Method for passivating III-V compound semiconductors |
US4244097A (en) * | 1979-03-15 | 1981-01-13 | Hughes Aircraft Company | Schottky-gate field-effect transistor and fabrication process therefor |
US4310362A (en) * | 1979-06-22 | 1982-01-12 | Thomson-Csf | Method of making Schottky diode with an improved voltage behavior |
US4426765A (en) * | 1981-08-24 | 1984-01-24 | Trw Inc. | Process for fabrication of ohmic contacts in compound semiconductor devices |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4694563A (en) * | 1981-01-29 | 1987-09-22 | Sumitomo Electric Industries, Ltd. | Process for making Schottky-barrier gate FET |
US4782031A (en) * | 1983-10-19 | 1988-11-01 | Matsushita Electronics Corporation | Method of making GaAs MOSFET with low source resistance yet having satisfactory leakage current by ion-implantation |
US4774200A (en) * | 1985-03-26 | 1988-09-27 | Sumitomo Electric Industries, Ltd. | Schottky-gate field effect transistor and method for producing the same |
US4889817A (en) * | 1985-08-08 | 1989-12-26 | Oki Electric Industry Co., Ltd. | Method of manufacturing schottky gate field transistor by ion implantation method |
US4640003A (en) * | 1985-09-30 | 1987-02-03 | The United States Of America As Represented By The Secretary Of The Navy | Method of making planar geometry Schottky diode using oblique evaporation and normal incidence proton bombardment |
US4706377A (en) * | 1986-01-30 | 1987-11-17 | United Technologies Corporation | Passivation of gallium arsenide by nitrogen implantation |
US4833042A (en) * | 1988-01-27 | 1989-05-23 | Rockwell International Corporation | Nonalloyed ohmic contacts for n type gallium arsenide |
US5030579A (en) * | 1989-04-04 | 1991-07-09 | Eaton Corporation | Method of making an FET by ion implantation through a partially opaque implant mask |
US5138406A (en) * | 1989-04-04 | 1992-08-11 | Eaton Corporation | Ion implantation masking method and devices |
US5011785A (en) * | 1990-10-30 | 1991-04-30 | The United States Of America As Represented By The Secretary Of The Navy | Insulator assisted self-aligned gate junction |
US5914500A (en) * | 1997-01-21 | 1999-06-22 | Abb Research Ltd. | Junction termination for SiC Schottky diode |
US20050017244A1 (en) * | 2003-07-25 | 2005-01-27 | Randy Hoffman | Semiconductor device |
US20050017302A1 (en) * | 2003-07-25 | 2005-01-27 | Randy Hoffman | Transistor including a deposited channel region having a doped portion |
US7262463B2 (en) | 2003-07-25 | 2007-08-28 | Hewlett-Packard Development Company, L.P. | Transistor including a deposited channel region having a doped portion |
US20070267699A1 (en) * | 2003-07-25 | 2007-11-22 | Randy Hoffman | Transistor Including a Deposited Channel Region Having a Doped Portion |
US7564055B2 (en) | 2003-07-25 | 2009-07-21 | Hewlett-Packard Development Company, L.P. | Transistor including a deposited channel region having a doped portion |
US20050199967A1 (en) * | 2004-03-12 | 2005-09-15 | Hoffman Randy L. | Semiconductor device |
US7250627B2 (en) | 2004-03-12 | 2007-07-31 | Hewlett-Packard Development Company, L.P. | Semiconductor device |
US20110068348A1 (en) * | 2009-09-18 | 2011-03-24 | Taiwan Semiconductor Manufacturing Company, Ltd. | Thin body mosfet with conducting surface channel extensions and gate-controlled channel sidewalls |
Also Published As
Publication number | Publication date |
---|---|
EP0070810B1 (en) | 1990-09-19 |
IT1171402B (en) | 1987-06-10 |
EP0070810A2 (en) | 1983-01-26 |
DE3280244D1 (en) | 1990-10-25 |
EP0070810A3 (en) | 1986-04-02 |
IT8148933A0 (en) | 1981-07-20 |
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